Device for establishing noise in a motor vehicle

ABSTRACT

In a device for establishing noise in a motor vehicle, comprising a housing which is divided by a sound transmission device into at least two spaces, of which one space is in communication with a gas-carrying part of an internal combustion engine arranged in the motor vehicle and the other space is acoustically coupled to an interior space of the motor vehicle via an outlet line, the outlet line is connected via a hollow rigid deflecting element to an interior space lining element, the rigid deflecting element being capable of transmitting forces applied thereto by the sound radiation to the interior space lining element.

This is a continuation-in-part application of international applicationPCT/EP03/03480 filed Apr. 3, 2003 and claiming the priority of Germanapplication 102 23 872.3 filed May 29, 2002.

BACKGROUND OF THE INVENTION

The invention relates to a device for establishing noise in a motorvehicle including a housing which is divided by a sound transmissiondevice into at least two spaces of which one is in communication with agas-carrying part of an internal combustion engine of the motor vehicleand the other space is acoustically coupled to the vehicle interior.

Such a device is known, for example, from DE 44 35 296 A1. Such devicesare intended to transmit the noises produced by the internal combustionengine more intensely to the driver of the motor vehicle, in particularduring acceleration, in order, on the one hand, to provide for a moreintensive driving experience and, on the other hand, to provide to thedriver more information concerning the load state of the engine.

The disadvantages of this known device, however, are its relatively lowefficiency and the very inflexible transmission characteristics.

DE 100 42 012 A1 attempts to improve the efficiency of the overalldevice. However, an optimum solution in particular with regard to moreflexible transmission characteristics is still not provided.

It is therefore the object of the present invention to provide a devicefor establishing noise in a motor vehicle by which the characteristicsof the transmission of the noises and their transmission from the engineinto the interior space of the motor vehicle are improved.

SUMMARY OF THE INVENTION

In a device for establishing noise in a motor vehicle, comprising ahousing which is divided by a sound transmission device into at leasttwo spaces, of which one space is in communication with a gas-carryingpart of an internal combustion engine of the motor vehicle and the otherspace is acoustically coupled to an interior space of the motor vehiclevia an outlet line, the outlet line is connected via a hollow rigiddeflecting element to an interior space lining element, the deflectingelement being capable of transmitting forces applied thereto by thesound radiation to the interior space lining element.

A deflecting element according to the invention between the outlet lineand the interior lining element has the effect that the sound waves thatare produced by the sound transmission device and introduced to thevehicle interior via the outlet line are deflected in the direction ofthe interior space, whereby an intensification of the sound effect isachieved. This intensified sound effect leads to a force acting on thedeflecting element, which then, on account of the connection of thedeflecting element to the inner lining element, induces the latter toundergo vibrations and in this way provides further intensification ofthe sound effect.

Therefore, in addition to changing the sound radiation there is also theadvantageous effect that vibrations of the interior lining element areproduced, so that overall considerably improved influencing of the noisein the interior space is possible by the device according to theinvention, enabling the driver to acoustically perceive the load stateof the engine.

The interior space of the motor vehicle can be insulated considerablybetter in this way for protection from disturbing external noises,without depriving the driver of acoustic information concerning the loadstate of the engine.

Decoupling the outlet line from the deflecting element, and theresultant possibility of intensifying the vibrations of the interiorlining element induced by the sound can be achieved if, in anadvantageous development of the invention, a flexible connecting elementis arranged between the outlet line and the deflecting element.

In a further advantageous refinement of the invention, the deflectingelement may be a hollow body. This represents an additional possibilityfor influencing the sound frequencies radiated into the interior spaceby varying the volume of the hollow body.

Advantageous refinements and embodiments of the invention will bedescribed below on the basis of the accompanying drawing:

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first basic embodiment of the device according to theinvention;

FIG. 2 shows a first development of the device of FIG. 1;

FIG. 3 shows a second development of the device of FIG. 1;

FIG. 4 shows a third development of the device of FIG. 1;

FIG. 5 shows a development of the device shown in FIG. 4; and

FIG. 6 shows a fourth development of the device of FIG. 1.

DETAILED DESCRIPTION OF THE VARIOUS EMBODIMENTS

FIG. 1 shows a gas-carrying line 1 of an internal combustion engine 2,which may be an exhaust line or an intake line of the engine 2. From thegas-carrying line 1, an inlet line 3 leads to a device 4 forestablishing engine noise in the interior of a motor vehicle, which isnot represented in its entirety the engine 2 being mounted in the motorvehicle in a way known per se.

The device 4, the basic construction and operating principle of whichare known for example from DE 100 42 012 A1, has a hollow body 5, in theinterior of which there is arranged a sound transmission device. Thesound transmission device in the present case is formed as a vibratablemembrane 6 and divides the hollow body 2 into two spaces, namely aninlet space 7 and an outlet space 8. Of these, the inlet space 7 isconnected to the inlet line 3 and the outlet space 8 is connected to anoutlet line 9 which leads to an interior space 10 of the motor vehicle.

Vibrations or sound waves inside the gas-carrying line 1, which areintroduced into the hollow body 5 via the inlet line 3, have the effectthat the membrane 6 is induced to undergo vibrations, which in turn areintroduced as sound waves into the interior space 10 via the outlet line9. In this way, the driver of the motor vehicle located in the interiorspace 10 is acoustically informed about the load state of the engine 2.

The outlet line 9 is connected via a deflecting element 11 to aninterior space lining element 12, a flexible connecting element 13 beingarranged between the outlet line 9 and the deflecting element 11. On theside that is opposite the flexible connecting element 13, the deflectingelement 11 is attached substantially rigidly to the interior spacelining element 12. The interior space lining element 12 is part of acomplete interior space lining 14, which at least partly lines theinterior space 10 in a way not represented, but may also be part of adashboard which is not represented.

The deflecting element 11, consisting for example of plastic, has theeffect that the sound waves arriving via the outlet line 9 aredeflected, which leads to an acoustic flow, and consequently to anintensification of the sound effect in the interior space 10. In thepresent case, the deflecting element 11 has for this purpose an angle ofsubstantially 90°, which has proven to be the most suitable for theintensification of the sound waves explained in more detail below. Ofcourse, an angle of the deflecting element 11 other than 90° isconceivable in particular installation cases.

The reacting force or counteracting force on the deflecting element 11that is produced as a result of the acoustic flow described and isindicated by an arrow causes the deflecting element to exert a force onthe interior lining element 12, which in turn induces the latter toundergo vibrations, and consequently to produce sound of its own. Thesevibrations of the interior lining element 12 intensify further thedescribed acoustic information for the driver with respect to the loadstate of the engine 2. In the present case, the interior lining element12 is decoupled from the interior lining 14, in order to prevent thecomplete interior lining 14 from vibrating and to offer the interiorlining element 12 an independent possibility of radiating vibration.This makes it possible to provide the interior lining element 12 with aspecial geometry, in order to achieve a further possibility forinfluencing the way in which sound is produced. However, this specialgeometry of the interior lining element 12 is not discussed herein indetail.

FIG. 2 shows a development of the device 4 based on FIG. 1. Arrangedherein at the outlet of the device 4, that is at the transition of thedeflecting element 11 into the interior space 10, is an absorptionmaterial 15, which influences the sound radiation into the interiorspace 10. The absorption material 15 may have an acoustic impedance of,for example, 40 rayl. The acoustic impedance that is produced results ina further force, which acts on the interior lining element 12.

FIG. 3 shows a further refinement of the device 4 shown in FIG. 1.Arranged herein at the outlet or transition into the interior space 10is a constricting element 16, which may be connected to the interiorspace lining element 12 or the deflecting element 11 and extends intothe interior space 10. The constricting element 16 has the effect ofincreasing the flow velocity from the deflecting element 11 into theinterior space 10, and consequently of achieving an intensification ofthe acoustic flow described above, which leads to a higher resultantforce on the deflecting element 11, and consequently also to a strongerinducement to vibrate.

A further configuration of the device 4 is represented in FIG. 4. Inthis case the deflecting element 11 has a hollow body 17, which isconnected via line elements 17 a and 17 b on the one hand via theflexible connecting element 13 to the outlet line 9 and on the otherhand to the interior lining element 12. The hollow body 17 achieves theeffect of further influencing the sound waves produced or passed on bythe sound transmission device or membrane 6, this influencing beingdependent of course on the form, and in particular the volume, of thehollow body 17 and being controllable by changing these variables. Toachieve the effect of inducing the interior lining element 12 to vibratein this case too, the hollow body 17 is connected to the interior liningelement 12 by means of a rigid, rod-shaped connecting element 18.

FIG. 5 shows a development of the embodiment according to FIG. 4. Inthis case the hollow body 17 has two volumes, namely a first volume 19and a second volume 20. The first volume 19 is connected via the lineelement 17 a and the flexible connecting element 13 to the output line 9and the second volume 20 is connected via the line element 17 b to theinterior lining element 12. For connecting the first volume 19 to thesecond volume 20, a further line element 17 c is provided. In this case,too, the hollow body 17 is connected via the rigid connecting element 18to the interior space lining element 12, for which purpose theconnecting element 18 extends between the interior lining element 12 andthe first volume 19.

FIG. 6 shows a further embodiment of the device 4, which in this casehas at the outlet into the interior space 10 a widening element 21,which, by contrast with the constricting element 16 according to FIG. 3provides a reduction of the reacting force on the deflecting element 11and consequently likewise serves for influencing the sound radiationinto the interior space 10.

All the embodiments that are represented in FIGS. 1 to 6 may be combinedwith one another in any way desired if they are not mutually exclusive.For example, the absorption material 15 may be provided in all theembodiments and the decoupling of the interior space lining element 12from the interior vehicle lining 14 may be provided in each case.

1. A device for establishing noise in a motor vehicle, comprising ahousing (5), a sound transmission device (6) disposed in the housing (5)so as to divide the housing (5) into at least two spaces (7, 8), aninlet line (3) extending between one of said spaces (7) and agas-carrying part (1) of an internal combustion engine (2) arranged inthe motor vehicle so as to be in communication with the gas carryingpart (1) and an outlet line (9) connected to the other space (8) of thehousing (8) for acoustically coupling the other space (8) to an interiorspace (10) of the motor vehicle, said outlet line (9) being connected toan interior lining element (12) of the motor vehicle via a hollow rigiddeflecting element (11) formed in such a way that it is capable oftransmitting forces applied to it to the interior space lining element(12) for transmitting the sound radiation into the interior space (10)of the motor vehicle.
 2. The device as claimed in claim 1, wherein aflexible connecting element (13) is arranged between the outlet line (9)and the deflecting element (11).
 3. The device as claimed in claim 1,wherein an absorption material (15) is arranged at the transition fromthe deflecting element (11) to the interior space (10).
 4. The device asclaimed in claim 1, wherein a constricting element (16) is arranged atthe transition from the deflecting element (11) to the interior space(10).
 5. The device as claimed in claim 1, wherein a widening element(21) is arranged at the transition from the deflecting element (11) tothe interior space (10).
 6. The device as claimed in claim 1, whereinthe deflecting element (11) is angled by at least approximately 90°. 7.The device as claimed in claim 1, wherein the interior space liningelement (12) is acoustically decoupled from an interior vehicle lining(14) at least partly lining the interior space (10) or from a dashboardarranged in the interior space (10).
 8. The device as claimed in claim7, wherein the deflecting element (11) includes a hollow body (17). 9.The device as claimed in claim 8, wherein the hollow body (17) has twoseparate volumes (19, 20), which are in communication with each other.10. The device as claimed in claim 8, wherein the hollow body (17) isconnected to the interior space lining element (12) via at least onerigid connecting element (18).